Recombinant BCG Expressing IL-12 as A Novel Immunomodulatory Strategy for Allergic Asthma: Opportunities and Challenges

Abstract

Allergic asthma is a chronic respiratory disorder driven by a T helper type 2 (Th2)-mediated immune response that involves eosinophils and mast cell recruitment to affected tissues, eliciting inflammatory cytokines and IgE production. Typical symptoms in more severe cases include wheezing, shortness of breath, chest tightness, persistent coughing, excessive mucus production, and airway hyperresponsiveness. Current therapies, which focus on suppressing the immune system, mitigate the symptoms but are generally insufficient to address the disease. Mycobacterium bovis bacillus Calmette-Guérin (BCG) platform, initially developed as an attenuated vaccine for tuberculosis (TB), induces a potent T helper type 1 (Th1) polarized immune response, making it a promising candidate for treating Th2-dominant conditions, such as allergic asthma, ultimately alleviating the symptoms. BCG can be genetically modified to express antigens of other pathogens or immunogenic proteins, such as IL-12p70. In this review, we examine the potential of BCG as a novel therapeutic platform for allergic asthma, focusing on its ability to modulate the immune response via IL-12.

Keywords: Allergic asthma; BCG; IL-12; Recombinant BCG; Th2; Therapeutic strategy.